The career development activities and research plan outlined in this Research Career Development Award (RCA) are designed to provide the means for the candidate to translate relevant aspects of neurobiology and independently formulate and implement psychopharmacologic treatment trials in pediatric bipolar disorder (BP). Pediatric BP is a devastating illness that can result in permanent disruption of a child's normal development, emotional suffering, aggression and suicide. Pharmacotherapy has been the cornerstone of the management and treatment of pediatric BP. However, there is very little controlled research addressing medication treatment of children and adolescents with BP. In addition, treatment research in child psychiatry has generally not addressed developmental differences in neurobiology or pharmacology, nor attempted to identify biological factors that may be predictors or mediators of treatment response. The proposed study will be the first dose-ranging study of a medication for depression in pediatric BP. It will explore the relationship between platelet 5-HT reuptake blockade and treatment response, as well as examine potential predictors of treatment response. The candidate is certified in child and adolescent psychiatry, and is completing the second year of an NIMH-sponsored post-doctoral research fellowship. Dr. James Perel, Professor of Psychiatry and Pharmacology and Director of the Clinical Pharmacology Program at the University of Pittsburgh's Western Psychiatric Institute and Clinic (WPIC) will serve as Sponsor. The coursework and directed readings in advanced topics of psychopharmacology, clinical trial design, developmental neurobiology and pharmacology, emotional regulation and circadian rhythm, will prepare the candidate to perform biologically-informed treatment research in pediatric BP.